tools: switch to Face::getIoContext()

Change-Id: I550dc4dd9dc6509b7df3104b8cd68865653df541
diff --git a/wscript b/wscript
index a4f9500..ec72c96 100644
--- a/wscript
+++ b/wscript
@@ -46,7 +46,7 @@
                    'For more information, see https://redmine.named-data.net/projects/nfd/wiki/Boost')
 
     if conf.env.WITH_TESTS:
-        conf.check_boost(lib='filesystem unit_test_framework', mt=True, uselib_store='BOOST_TESTS')
+        conf.check_boost(lib='unit_test_framework', mt=True, uselib_store='BOOST_TESTS')
 
     if conf.env.WITH_TOOLS:
         conf.check_boost(lib='program_options', mt=True, uselib_store='BOOST_TOOLS')